Update env_logger requirement from 0.5.11 to 0.6.0

Updates the requirements on [env_logger](https://github.com/sebasmagri/env_logger) to permit the latest version.
- [Release notes](https://github.com/sebasmagri/env_logger/releases)
- [Commits](https://github.com/sebasmagri/env_logger/commits/v0.6.0)

Signed-off-by: dependabot[bot] <support@dependabot.com>

Author: dependabot-support

Cargo.toml

@@ -24,7 +24,7 @@ crossbeam-utils = "0.5"
 crypto-hash = "0.3.1"
 curl = { version = "0.4.19", features = ['http2'] }
 curl-sys = "0.4.15"
-env_logger = "0.5.11"
+env_logger = "0.6.0"
 failure = "0.1.2"
 filetime = "0.2"
 flate2 = "1.0.3"